Azo dyes from bis (p-aminophenyl) butadienes



AZO DYES FROM BIS(p-AMINOPHENYL BUTADIENES Leon Katz, Springfield, andDelton W. Hein, Somerville, N.J., John E. Pretlra, Wilmington, Del., andRobert S. Long, Bound Brook, N..l., assignors to American CyanamidCompany, New York, N.Y., a corporation of Maine No Drawing. ()riginalapplication September 7, 1954,

' Serial No. 454,642, new Patent No. 2,852,556, dated September 16,1958. Divided and this application November 30, 1955, Serial No. 550,177

9 Claims. (Ci. 260- 178) This invention relates to new intermediates andto the dyes, pigments and brighteners derived therefrom. Morespecifically, it relatesto 1,4-bis (para-aminophenyl)- butadienes, to1,4-bis (para-aminophenyl)butadiene-l-carboxylic acid and1,4-dicarboxylic acid, to the corresponding acyl and alkylaminocompounds, and to azo dyes and pigments derived from the free aminocompounds.

The butadiene system has previously been known in dyestufi chemistryonly in certain isolated cases, such as the light-sensitive 'cyaninedyes which are used as photosensitizers and desensitizers.

We have found that l,4-bis(para"-aminophenyl)-1,3- butadienes and theirring substitution products are good intermediates for the preparation ofdyes, pigments and brighteners, and that the various coloring mattersthus obtained have excellent properties. The 'acylamino and alkylaminoderivatives of the diphenylbutadiene system fluoresce and are goodbrighteners. The azo derivatives obtained from1,4-bis(para-aminophenyl)butadiene are good dyes of shades which in manycases are unusually deep and very useful.

Fluorescence alone is not enough to make good brighteners. The compoundmust also be substantive to the cloth, must be itself relativelyuncolored, and must fluoresce in the visible in the blue range in orderto cancel out the natural yellow of the cloth. While diphenylbutadieneis uncolored, the addition of the strongly auxochromic amino groupswould have been expected to produce color in the molecule. It isunexpected to find that the corresponding acylamino and alkylaminoderivatives'not only are relatively uncolored but that they 212-o-anrO-ono i aim-Geno l 2,913,450 Patented Nov. 17, 1959 ice possessgood substantivity to the cloth, fluorescence in the blue range of thevisible, and have good fastness properties. These properties would notbe predicted.

While stilbene compounds have been used in dyes and brighteners, therewere definite reasons to expect that the diphenylbutadiene structurewould be unusable. The high reactivity of the butadiene system leads oneto an expectation that the dyes derived from diphenylbutadiene would bemuch more unstable. This however is not observed. Increase inconjugation normally has the effect of shifting the color of compoundsinto the visible. Many stilbene brighteners are already pale yellow andit was expected that the 1,4-diphenylbutadiene compounds would have apronounced color in the visible. We were therefore very much surprisedto find that this was not so, and that the 1,4-bis(para-acylaminoandalkylaminophenyl)butadienes are still relatively uncolored.

Substantivity is believed in the art to be a function of hydrogenbonding between the dye and the fiber and is therefore a function of therelative geometry of the fiber and dye molecules. The increase in thechain length of the butadiene derivatives 'of'our invention over thecorresponding stilbene derivatives made it unpredictable that thecompounds of our invention would be substantive. They are in fact,however, quite substantive.

For certain uses where water solubility is important derivatives can beprepared in which a carboxy group is substituted on the butadiene chain.In other cases, where such solubility is not desired, as for example inpigments and brighteners for non-'cellulosic fibers, the best intermediate is a 1,4-bis(para-aminophenyl)-1,3-butadiene free of carboxygroups.

Uncarboxylated products are prepared by the condensation of ap-acylaminobenzaldehyde with succinic anhydride to give a 1,4-bis(p-acylaminophenyl) 1,3-butadiene which may be hydrolyzed to the freeamino compound. Alternatively, a {p-nitrob'enzaldehyde is condensed withsuccinic anhydride, and the resultant1,4-bis(p-nitrophenyl)-1,3-butadiene on reduction yields the samecompound. If desired, this can then be acylated to give an acylderivative; There are thus two alternative routes available to eitherthe acylamino or the aminophenyl butadienes and the choice of the routewill depend on the circumstances. If the acyl group is such that it willbe unalfected by the reaction conditions, the procedure starting with anacylaminobenzaldehyde is the best one to use to obtain an acylderivative. Where the acyl group may be aifected an alternative route ischosen. These reactions can be illustrated by the following equations:

CHr-CO NHr-CH=CH NHPOGH=JEH Hr-CO GOOH Among the acylamino benzaldehydeswhich are usable in the synthesis of compounds of this invention, therecan be named the formyl, acetyl, propionyl, butyryl, benzoyl,para-toluyl, ortho-toluyl, ortho-methoxy benzoyl, dimethoxy benzoyl, andthe like derivatives of paraaminobenzaldehyde and similar derivatives of2-chlor-4- aminobenzaldehyde, 2-6-dichlor 4 aminobenzaldehyde,4-amino-2-nitrobenzaldehyde, 4-amino-3-methylbenzaldehyde,4-amino-6-chlor-3-methylbenzaldehyde, 3-methoxy- 4-aminobenzaldehyde.

Among the para-nitrobenzaldehydes usable in alternative processes arepara-nitrobenzaldehyde, 2-chlor-4- nitrobenzaldehyde,S-hydroxy-4-nitrobenzaldehyde and 3-methoXy-4-nitrobenzaldehyde.

Other intermediates usable in the preparation of compounds of ourinvention are para-nitrocinnamaldehyde and halogen derivatives thereof,2-4-dinitrocinnamaldehyde, 2-carboxy-4-nitrocinnamaldehyde and similarcompounds and para-nitrophenyl-acetic acid, 2-chlor-4-nitrophenylaceticacid, 3-hydroxy-4-nitrophenylacetic acid and3-methoxy-4-nitrophenylacetic acid and the like. In the case of the monocarboxy derivatives unsymmetrical derivatives can be prepared by theproper choice of the nitro cinnamaldehyde and nitro phenyl acetic acidto be used.

The acylarnino derivatives of 1,4-bis(p-aminophenyl) butadiene fluoresceand are readily usable as brighteners. As acyl groups one can use thebenzoyl group; alkylbenzoyl groups, such as o-toluyl, p-toluyl;alkoxybenzoyl groups such as p-anisoyl, o-ethoxybenzoyl, 2,4dimethoxybenzoyl, 2,5-diethoxybenzoyl and the like; amino derivativessuch as p-aminobenzoyl; halogen derivatives such as p-chlorobenzoyl,2,4-dichlorobenzoyl, and the like; or aliphatic acyl derivatives such asforrnyl, acetyl, propionyl, butyryl and the like. These acyl derivativesmay be prepared either from the 1,4-diphenyl butadienes from thecorresponding diphenyl butadiene carboxylic acids or from nuclearsubstitution products of any of these.

Alkyl derivatives of these amino compounds also fluoresce. Those withoutcarboxy groups are especially good brighteners for non-cellulosicfibers. They are either prepared by the alkylation ofl,4-bis(p-aminophenyl)-1,3-butadiene or by synthesis starting withdialkylaminobenzaldehyde in the place of the acylaminobenzaldehyde.Alkylation of the aminophenylbutadiene can be carried out either by theuse of alkyl sulfates or alkyl halides. Lower alkyl derivates are bestprepared by the use of the dialkyl sulfates while the alkyl halides aremore available in the case of the higher alkyl groups. When mono-alkylderivatives are desired, they are prepared by synthesis starting with anacylated monoalkyl amino benzaldehyde which is condensed with succinicanhydride followed by deacylation.

We have further found that azo dyes and pigments of interestingproperties are preparable by the tetrazotization of thebis(aminophenyl)butadienes followed by coupling to the usual couplingcomponents. The bis(aminophenyl) butadienes are especially good as fastbases when coupled into naphthols such as the arylides ofbeta-oxy-naphthoic acid. One can also couple to sulfonated compoundssuch as naphthol sulfonic acids or amino naphthol sulfonic acids toproduce direct dyes. Among these coupling components arel-naphthol-Z-sulfonic acid, 1-naphthol-2,7- disulfonic acid,2-naphthol-4-sulfonic acid, Z-naphthol- 3,6-disulfonic acid, Z-naphthol3,6,8 trisu1fonic acid, S-amino-1-naphthol-5.7-disulfonic acid,S-amino-l-naphthol-3,6-disulfonic acid, and the like. The preparation ofdirect dyes is not limited to naphthols since any other sulfonatedcoupling component can equally be used. With relation to the directdyes, it was obviously not predictable whether increase in the length ofthe molecule would have a harmful efiect On the substantivity of thedyes for cellulosic materials. We have found in fact that thesubstantivity is not impaired.

We have also found that the butadiene structure has a bathochromicetfect on the shade when compared with dyes from the correspondingstilbenes or benzidines. This is a very important observation since itprovides a means to obtain very greenish blue shades which cannotnormally be obtained with simple azo dyes. This is particularly true ofdyes derived from 1,4-bis(3-methoxy-4- aminophenyl)butadiene and relatedcompounds. These dyes are of particular interest because the methoxygroups permit metallization when the coupling component has metallizablegroups, such as hydroxyl or amino ortho to the azo group, andmetallization generally leads to improved fastness to light. Dyes ofthis type may be represented as follows:

0 ll ll chroma-Quinnn-on=on-NH-o-om A mixture of 89.5 parts ofp-acetaminobenzaldehyde, 27.5 parts of succinic anhydride, 57.5 parts oflitharge, and 75 parts of acetic anhydride is stirred at the boil untilthe condensation is complete. It is then cooled and diluted with 75parts of acetic acid followed by parts of methanol. The precipitatedproduct is then isolated by filtration and reslurried in 250 parts ofmethanol. This slurry is boiled, cooled, and filtered. The product ob-Example 2 A mixture of 3.2 parts of the above product of Example 1, 5.6parts of potassium hydroxide, and 25 parts of anhydrous alcohol isstirred at the boil until hydrolysis is complete. The mixture is thenpoured into 100 parts of cool water and the precipitated solid isisolated by filtration and washing.

A mixture of 4.8 parts of the product from Example 1, 24 parts ofethanol, and 18 parts of cone. hydrochloric acid is refluxed untilhydrolysis is complete. After the mixture is cooled, the solid isisolated by filtration, Washed with ethanol, and then with ether. Thedihydrochlorideis transformed to the free base by dissolving in hotwater, alkalizing, and isolating in the usual Way. The solid, identicalto the product produced by the procedure of the first paragraph of thisexample, is purified by recrystallization from toluene givingbrownish-yellow granules.

Example 3 COOH 4.53 parts of p-nitrophenyl acetic acid and 2.75 parts oflitharge are thoroughly mixed. The mixture is then slurried in 20 partsof acetic anhydride and the slurry is heated to boiling. 4.43 parts ofp-nitro-cinnamaldehyde is added and the mixture is heated at the boiluntil reaction is substantially complete. The precipitated product isfiltered hot and Washed with water. The crude product may be purified byreprecipitation from sodium carbonate solution With acid and can also berecrystallized from acetic acid. It is 1,4-bis(p-nitrophenyl)-1-carboxy-1,3-butadiene.

When an equivalent quantity of 2,4-dinitropheny1- acetic acid is used,one obtains 1-(2,4-dinitrophenyl)-4- 4-nitrophenyl) -1-carboxy-1,3-butadiene.

6 gradually and the reaction mixture is boiled until the reduction issubstantially complete. The mixture is clarified by filtration and thefiltrate is carefully neutralized with dilute hydrochloric acid. Theprecipitated product is isolated by filtration and washing. It may bepurified by reprecipitation from sodium carbonate solution with acid.

Example 5 OOH OOH 5.6 parts of sodium hydroxide is dissolved in 100parts of water. 7.24 parts of p-nitrophenyl acetic acid is added and thesolution is cooled. 3.86 parts of 30% aqueous glyoxal is then added andthe mixture is stirred at 0 C. for a short time followed bystirn'ng atroom temperature until the reaction is substantially complete. Theproduct is isolated by filtration and dissolved in boiling water. Thesolution is salted with saturated brine and cooled to room temperature.The light yellow orange solid, Which separates, is isolated byfiltration and washing. It is the disodium salt of1,4-bis(p-nitrophenyl)-1,4-bis(carboxy)- 1,3-butadiene.

Substituted 1,4 bis(p -nitrophenyl -1,4 bis(carboxy)-1,3-butadienes inWhich the aromatic ring are correspondingly substituted, are obtainedwhen there is substituted for the p-nitrophenyl acetic acid equivalentamounts of 2-chloro-4-nitro-phenylacetic acid, and 3-methoxy-4-nitrophenyl acetic acid.

Example 6 coon OOH The procedure of Example 4 is followed, using 1.16parts of the product of Example 5 instead of 1.0 part of the product ofExample 3. The product is 1,4-bis(paminophenyl) -l,4-bis carboxy)-1,3-butadiene.

Example 7 23.6 parts of the product of Example 2 is mixed with 250 partsof pyridine. 17 parts of benzoyl chloride is added gradually and themixture is stirred at 50-75 C. until acylation is complete. The mixtureis diluted with 500 parts of water, sodium carbonate added, and thepyridine is removed by distillation. The prod uct,1,4-bis(p-benzoylaminophenyl)-l,3-butadiene, is isolated by filtrationand washing.

By starting with 18 parts of o-toluyl chloride, 19 parts ofp-anisoylchloride, 24 parts of 2,4-dimethoxybenzoylchloride, or 21 partsof o-chlorobenzoylchloride, the correspondingbis(acylaminophenyl)butadiene is prepared by the same procedure.

Example 2 Example 4 OOH One part of the product of Example 3 is slurriedin 25 parts of concentrated ammonia and the mixture is COOH heated tothe boil. Five parts of ferrous-sulfate are added 1,3 -bis(alkoxybenzamidophenyl)-1-carboxy butadiene.-

'7 Example 9 Z C O OH ooort Example Cg; /OH3 O 3 COOH OOH CH3 A mixtureof 23.6 parts of the product of Example 6 with 250 parts of water andparts of sodium carbonate is alkylated with excess dimethyl sulfate,sodium hydroxide being added as needed to maintain alkalinity tophenolphthalein. After alkylation is complete the reaction mixture isthen heated to 80-90 C. for a short time usual manner are dyed with thetetrazo solution. The

following colors are obtained:

3-hydroxy-2-naphthoic anilide (Naph- Reddish-blue.

thol AS).

2-methyl-3-hydroxy-2-naphthoic anilide Reddish-blue.

(Naphthol ASD).

4,4'-bis(acetoacetamido)3,3 dimethyl Yellow-orange.

biphenyl (Naphthol ASG). 2',5'-dimethoxy 3 hydroxy 2 naphthoic anilide(Naphthol ASBS). 3-nitro-3-hydoxy-2-naphthoic anilide Reddish-blue.

Maroon.

2'-ethoxy-3-hydroxy-2-naphthoic anilide Blue.

(Naphthol ASRL).

2'-methyl-4'methoxy 2 hydroxy- 11- Yellow-gray.

benzo( a) carbazole 3 carboxanilide (Analog of Naphthol ASDB).

2 acetoacetamido 6 ethoxy benzothi- Reddish-tan.

az ole (Naphthol ASL G).

Example 14 to hydrolyze any methyl ester which is present. Acidification(after clarification if necessary) precipitates the 1,4 bis(pdimethylaminophenyl) 1,4 -dicarboxybutadiene. 7

Example 11 The procedure of Example 1 is followed, substituting 83 partsof p-nitrobenzaldehyde for the acetylaminobenzaldehyde. The resultant1,4 bis(p nitrophenyl)- butadiene can be reduced by the procedure ofExample 4 to give a product identical with that of Example 2.

Example 12 oHH-NHQ-oBEoH-omenQ-nmom The procedure of Example 1 isfollowed, using 228 HOaSWOS 0 IE A suspension of 1.08 parts of 1,4-bis(p-arninophenyl)- 1,3-butadiene in 25 parts of water strongly acidifiedwith hydrochloric acid was tetrazotized in the usual fashion at 10 C.The tetrazo solution was clarified and added portionwise to a solutionof 2.86 parts of 2-naphthol-3,6- disulfonic acid disodium salt in 50parts of water containing 0.4 part caustic. The mixture was stirreduntil coupling was essentially complete, with additions of soda ash whennecessary to maintain a positive test on Brilliant Yellow paper. Thecoupling product was isolated and purified further by reprecipitating itfrom a solution in dilute caustic by addition of sodium acetatecrystals.

7 The dye exhausted rapidly onto cotton giving a'blue shade, appreciablegreener in hue than the corresponding dyes from 4,4-diaminostilbene andbenzidine.

parts of p-octadecylacetarninobenzaldehyde (prepared by Example 15 I HzNOH ()H lTlH: H0 5 N=NGH=OHCH=CHN=N som S0 11 sonz Example 13 v Theproduct of Example 2 is tetrazotized in the usual manner. Cotton clothspreviously printed with pastes of naphthols of the Naphthol AS seriesprepared in the The procedure of Example 14 is followed substituting anequivalent amount of Chicago acid (1-amir1o-8-naphthol-2,4-disulfonicacid) for R-salt (2-naphthol-3,6-disulfonic acid). The product dyescotton and rayon an attractive greenish-blue shade, greener than thatfrom the dye of Example 14;

We claim:

1. A20 compounds of the formula in which R is a 1,4-bisphenyl butadienein which each azo link is attached to a different phenyl in a positionpara to the butadiene linkage and in which Ar is the residue of acoupling component selected from the group 5. The compound which has theformula consisting of unsubstituted naphthols, naphthol sulfonic OH I lacids, amino-naphthol sulfonic acids and coupling com- 6. The compoundwhich in the free acid form has the ponents of the Naphthol AS series.formula HEN OH OH NH: Hots -N=N-C OH=CHCH=CHN=N S03H 2. A20 compounds ofclaim 1 in which the said cou- I 7. The compound which in the free acidform has the pling component is a naphthol sulfonic acid. formulaN=NOH=CH-GH=CHON=N OH 7 HO HO; so n H058 S0,

3. The azo compounds according to claim 1 in which 8. The compound whichhas the formula N=NC CH=OHOH=CH N=N o HO H -c O-NHQ QNH-JJO 7 C23: 02115the said coupling component is an aminonaphthol sulfonic acid. 9. Thecompound which has the formula N=NC GH=OHCH=CH-C N=N 0H 03,0 cH,o 110-CHHQ QNMW 4. A20 compounds of the formula I References Cited in the fileof this patent AFN: OGHwH-CECHGMNW 2,632,004 EI SefZf EifiTi E L /Iar.17, 1953 ECZZEi'FOQ .11 gifli ififisiiifijfii liiifilfifi filfifii 60OTHER REFERENCES thols, naphthol sulfonic acids, aminonaphthol sulfonicLubs: Chemistry of Synthetic Dyes and Pigments, 1st.

acids and coupling components of the Naphthol AS edition, 1955, p. 664.series,

1. AZO COMPOUNDS OF THE FORMULA